Rail-insulator.



PATENTED DEC. 22, 1903.-

' L. M. RANDOLPH.-

RAIL INSULATOR.

APPLICATION FILED MAY 4. 1903. v

N0 MODEL.

THE cams PETERS co, Pno'm-umc. mwmsvow u c.

UNITED STATES Patented December 22, 1903.

LEONARD M. RANDOLPH, or NEWARK, NEW JERSEY.

RAIL-INSULATOR.

SPECIFICATION forming part of Letters Patent No. 747,477, dated December22, 1903.

Application filed May 4, 1903- Serial No. 165.491. (No model.)

To all whom. it may concern.-

Be it known that I, LEONARD M. RAN? This invention relates torail-insulatingdevices, and particularly to insulating devices for railslaid upon or in the ground and serving as conductors of electricity.

It is well known that in uninsulate'd groundrails a constant leakage ofcurrent takes place at every point, thus causing a material loss ofcurrent, as well as seriously aifecting adjacent water-pipes and otherunderground metallic conduits, into which the current escapes and setsup a continuous electrolytic action. Heretofore various means have beendevised to insulate ground-rails to prevent this leakage, recoursehaving been had to the embedding of such rails in concrete and to thelaying of bricks or tiles around the rails. The objection to the use ofsuch devices for insulating ground rails has been that owing to theporosity of the concrete, cement, and of the brick and tile the moisturein the ground has easily penetrated these substances and rendered themfairly good conductors. Furthermore, the spaces between adjacent bricksand tile has permitted Water to collect therein in wet weather, whichwater would form a continuous conductor from the rail to the dampearth,into which the electricity from the rails would easily escape.Another objection to these insulating-rail devices is that they arebrittle, and therefore are liable to crack, chip off and crumble, thusdestroying the continuity of the insulation, and consequently afiordingnew avenues for leakage.

The object of the present invention is to provide an insulating-coveringfor groundrails, which covering shall be adapted to be laid about therails so as to form acontinuous coveringthat is, a covering in which"there shall be no intervening spaces, as is the case with bricks andtiles, and which covering shall also be non-porous and adapted toinsulate the rails under all conditions.

In the accompanying drawings, in which the invention is illustrated,Figure 1 is a transverse section of a T-rail around which theinsulating-covering has been laid, and Fig. 2 isa transverse section ofa common form of street-car rail around which the insulatingcovering hasbeen laid and also a'layer'of cement or concrete and showingpavingstones laid around the rail.

Inorder to provide a suitable non-porous insulating-covering adapted forthe purpose in hand, a substance known in the trade as varnish residueor varnish mud is preferably employed, although any other non-porousplastic substance may be used. This substance comprises the settlings orwaste which adheres to the varnish kettles or tanks after the refinedvarnish has been removed,and it is of a plastic or gu mmy nature andcapable of being easily molded into any desired shape or form or ofbeing applied to the surface of any object to form a coating orcovering. If the varnish residue when taken from the kettles or tanks isof too thin a consistency to be molded, it may be boiled until asufficient quantity of oil is removed therefrom to render it moreviscous. Instead of boiling the varnish residue, however, it ispreferable to mix it with cement, sand, or any absorbentsubstance,asuflicient quantity of cement or sand or other substance being used torender the resulting mixture of a proper consistency for molding.

In applying this insulating substance (varnish residue or varnishresidue and cement or sand) to a rail (1 the sides and base of the railare covered with as thin a coat 1) of the substance as is convenient toapply, and atterward, if desired, a layer of cement or concrete c, Fig.2, may be applied, which acts as a protective coat, although aprotective coat is by no means a necessity, as the insulating-coating ofvarnish residue 1) will grad ually set and become quite hard. Theinsulating-coating may be molded about the rail in any suitable manner.It is laid about the rail so as to be continuous at all points, therebeing no cracks or spaces in the same where water might collect orthrough which a leakage of current could in any manner take place. Assoon as the rail has been coated with the sure is preferably appliedaround the same in order to harden the coating and to press it intointimate contact with the rail. If a layer of concrete or cement c is tobe added over the insulating-coating b, as shown in Fig. 2, the pressuremay be applied after this layer of concrete or cement has been laid, andthe concrete or cement, as shown in Fig. 2, is preferably molded so asto present a squared exterior. This extra layer of concrete will beadded as a rule whenthe rail is laid between paving-stones d.

A'coating of varnish residue laid around the rails on a track in themanner above described or in a similar manner will insulate the railcompletely from any adjacent matter. Such a covering is also especiallyadapted to be used around the rails of a track, inasmuch as the joltingand vibration of the same will not cause this covering to crack or tocrumble or to become disintegrated in any way, and for this reason thecontinuity of the insulation will always be preserved.

I claim as my invention 1. A non -porous insulating-covering for railsconsisting of varnish residue and an absorbent substance laid around therail and pressed into intimate contact therewith, substantially asdescribed.

2. The combination withaconducting-rail of acontin uousinsulating-coverin g consisting of a non-porous plastic substance laidaround said rail and pressed into contact therewith, substantially asdescribed.

3. The combination with a conducting-rail o E a contin uousinsuIating-coverin g consisting of a substance of a gummy nature mixedwith sand or other absorbent substance, said covering being laid aroundthe rail and pressed LEONARD M. RANDOLPH.

Witnesses:

ANTHONY N. J ESBERA, LUCIUS E. VARNEY.

